Lightweight, variable, and high resistance machine

ABSTRACT

The invention relates to a resistance machine, e.g., for exercising. In particular, the machine is lightweight, compact, and modular to allow for ease of transportation and storage. The multifunction machine is also capable of providing variable and high resistances for many types of weight training methods, such as powerlifting.

CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY

This application claims the priority of U.S. Provisional Application No. 63/193,933 filed Mar. 27, 2021, which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a resistance machine for exercising. In particular, the machine is lightweight, compact, and modular to allow for ease of transportation and storage. The multifunction machine is also capable of providing variable and high resistances for many types of weight training methods, such as powerlifting.

BACKGROUND OF THE INVENTION

Currently, resistance training usually requires a user to have access to weighted plates, an Olympic bar, and racking equipment to perform these high resistance exercises. The overall system for performing these resistance exercises is bulky, heavy, and costly. Therefore, there remains a need for a system which allows users to perform high resistance exercises without the need for heavy or expensive equipment and which is lightweight, compact, and portable.

Many inventions have attempted to provide various features of the lightweight, variable, and high resistance machine, but no inventions to date contain all the features that the machine delivers to the user. The demand for personal fitness equipment is at an all-time high, yet there remains a need for a high resistance, variable resistance, lightweight, compact, portable, multifunction, and cost-efficient machine for fitness equipment users.

There are currently several electromechanical resistance machines available, such as Tonal Systems' U.S. Pat. No. 10,881,890 B2, which aim to give users an all-in-one gym in a compact form factor. These machines are effective in delivering these features, yet they are inherently unable to match the portability that a fully mechanical system offers. Mechanical systems have no reliance on power sources, and so there is no location of use limitation created. Electromechanical systems are also often more expensive given the complex nature of the design and the components used to create high resistances from electrical sources.

Other inventions attempt similar designs as those suggested in this patent, but they fail to deliver all aspects of the lightweight, variable, and portable resistance machine. Perhaps the most conceptually similar invention is ICON Health & Fitness' U.S. Pat. No. 10,441,840 B2. The invention delivers resistance in a collapsible form factor wherein the user stands upon a platform and pulls on cables connected to an upright cable arm system. The invention is compact, portable, and cost-efficient, but the upright cable arms prevent truly high resistances from being possible without significant structural weight being added to the frame. The upright frame also creates challenges in delivering a variety of different exercises to the user. Additionally, the invention has no concrete plan to deliver resistance, although it mentions the use of a flywheel resistance mechanism. While able to be lightweight and compact, the flywheel resistance mechanism is not practical in terms of delivering high resistance to users.

Another conceptually similar invention is Gymflex Fitness's U.S. Pat. No. 7,591,763 B 1. This machine offers users a multifunction, cost-efficient, portable, and lightweight resistance machine by providing the user with a convertible bench with spooled elastic resistance bands beneath the bench. However, the invention is not capable of delivering variable or high resistances to users. The lack of variable and high resistance capabilities limits the number of users that find the invention useful because users are unable to progress in their training.

SUMMARY OF THE INVENTION

A first objective of the invention is to provide a lightweight resistance machine wherein a user can perform high resistance exercises such as the bench press, deadlift, or squat. The invention aims to allow users to perform these exercises without the need for heavy or expensive equipment.

A second objective of the invention is to provide a compact resistance machine. As mentioned previously, current high resistance equipment is both heavy and bulky. For a user to own high resistance equipment, one must also have the space to store the equipment. This is an insurmountable obstacle to owning exercise equipment for many that live in smaller homes and apartments. Compacting a high resistance machine into a portable and lightweight package makes owning exercise equipment possible for many users.

A third objective of the invention is to provide a modular system. By providing a modular system, users can add resistance machines to their equipment to achieve higher levels of resistance than what is achievable with a single resistance machine. This provides the user with the flexibility to choose what resistance levels are appropriate for them. Additionally, the resistance machine can remain lightweight and portable without increasing the weight of a single machine.

A fourth objective of the invention is to provide an easily modifiable system. Maintaining ease of modification allows the user to quickly transition between exercises and maximizes the efficiency of the user's workout. The number of modular accessories should be limited to minimize equipment transition time and needed space for the resistance machine. It is also critical to allow the user to seamlessly select different levels of resistance without the need to disassemble modularized equipment.

A fifth objective of the invention is to provide an “all-in-one” resistance machine where most, if not all, traditional resistance exercises are possible. Giving the user as many exercise options as possible increases the likelihood that the user will purchase the invention to replace weight-based equipment. It is desirable to allow users to perform both the stated high resistance exercises and lower resistance exercises such as chest flies, lateral raises, and curls.

To achieve these objectives, a novel mechanism that combines the use of variable and lightweight resistance with dependent motion dynamics is designed. The mechanism is designed to be as small as possible and to be contained within an encasing. The user stands on the encasing and interacts with a single inelastic cable that contains the tensile force provided by the mechanism. Because the resistance force created by the mechanism is non-gravitational, the user's weight must be entirely contained within the machine system to ensure that the system is stable. Otherwise, the resistance is not internal to the overall system and external forces will dominate the response of the machine. Given the compactness of the machine, accessories are used to combine multiple resistance machines and modularize the resistance system. For example, a platform accessory is used to combine the forces of two separate resistance machines, thereby allowing the user to double the overall resistance and interact with two inelastic cables instead of one (FIG. 16 ). Additional accessories build on the platform accessory to allow the user to perform different exercises. For example, a bench accessory can be attached to the platform to allow the user to perform exercises that involve the use of benches. This design creates a fully modular environment wherein the user can quickly modify the resistance system to perform specific exercises.

A diverse set of complexities arise when designing the resistance mechanism contained within the modular resistance machine. Foremost, the lightweight and variable resistance must be designed. Lightweight and variable resistance can be provided in various manners including, but not limited to, electromagnets, electrically powered motors, resistance bands, and springs. For a lightweight, portable, and high resistance machine, the following design objectives are of the greatest importance minimizing the overall weight and volume, maximizing the overall resistance, and maximizing the independence of the overall system. To achieve these goals, two high-level approaches to the design of the lightweight resistance system are apparent: an electromechanical approach or a fully mechanical approach.

The electromechanical approach involves the conversion of electrically powered resistance devices, such as electromagnets or motors, into mechanical forces that the user interacts with. This approach greatly simplifies the mechanical design of the system due to the inherently variable nature of the mechanical force provided by electrical devices. To vary resistance, one must vary the power supplied to the resistance device. From a mechanical perspective, this is an advantageous design because it is compact and has no dynamically moving parts. Therefore, there are fewer chances for part failure. However, a power source is required to operate an electromechanical resistance machine. Additionally, the ability to output high resistance is proportional to the supplied electrical power, therefore causing faster battery drain at higher resistances. For a resistance machine attempting to provide high resistances in a portable system, these design limitations are not ideal because they create a dependence on available electrical power. A fully mechanical system that operates without these requirements is currently a more desirable and sustainable design.

The fully mechanical approach generally involves the use of multiple spring-based resistance devices that are selectively engaged by the user to vary resistance. There are many ways to achieve this, however, it is advantageous to create a system wherein the resistance is varied from a single point, such as weight selector pins or dials on traditional, weight-based resistance machines. In particular, a dial-based selector approach provides advantages over other resistance selecting mechanisms including increased modularity, ease of modification, and well-defined system arrangements. The use of a dial allows for gear meshing into other accessories to always give the user direct access to change the resistance. For example, if a platform accessory is placed over the top of a resistance machine, the dial is locked into a shaft hub that is connected to a second dial on the platform which is accessible to the user. The dial can also have defined locking positions which decreases reliance on the user to correctly engage resistances.

With any selector mechanism, a mechanical system must be designed to interface with the engagement of the spring-based resistance devices. Unlike electromechanical systems, fully mechanical systems are not inherently compact or variable. Many more design considerations must be accounted for to create a small, lightweight, variable, and high resistance mechanism. Although the fully mechanical system creates more mechanical design challenges, it operates independently from external conditions. Therefore, it is a more desirable and sustainable design approach as compared to the electromechanical approach because a mechanical approach increases the autonomy of the resistance machine.

For any approach to create variable and lightweight resistance, a part or assembly of parts must interface between the resistance device and the inelastic cable that the user interacts with. Herein, the part or assembly of parts that interfaces with both the resistance device and user-interfacing cable is referred to as the “interfacing device”. Because typical user exercises can involve at least three feet of cable travel, the challenge of limiting the distance of travel for the resistance device is always present to create a compact and modular machine. Therefore, a dependent motion system that increases the ratio of the distance traveled by the inelastic cable compared to the resistance device must be utilized. This ratio is referred to herein as the “distance traveled ratio”. There are many ways to increase the distance traveled ratio from a mechanical standpoint, including gear, pulley, and belt systems. To increase the reliability of the system, it is advantageous to use pulley systems because they contain low precision requirements, do not require spooling, and are easily maneuverable when designing the system.

When increasing the distance traveled ratio, the tension in the inelastic cable decreases by an inversely proportional amount. This is an important consideration to factor into the design of the system because it works against the production of high resistance. For example, a pulley system using a distance traveled ratio of two to one requires a total resistance output of 500 lbs from the resistance mechanism to output 250 lbs of tension to the user. Therefore, it is important to limit the distance traveled ratio to decrease the total resistance requirement for the resistance mechanism. Systems designed with higher distance traveled ratios have higher internal stresses and require more robust frames, increasing the overall weight and cost of the resistance machine.

To design a portable system, there is a general goal to limit the height of the resistance machine. With a limiting height, resistance devices must be carefully chosen to fit within the resistance machine encasing. Additionally, the fatigue life of the devices must be considered because of the high usage that the resistance machine will undergo. Resistance bands or coiled springs are potentially useful resistance devices due to their ability to output high resistance and ease of replacement. However, the stress response of rubber and coiled springs is highly nonlinear and relies upon the initial unstretched length. The total stretch of these devices also must be limited to maintain a high fatigue life. For rubber, limiting the maximum stretch ratio to 1.75 (stretched a distance equal to 75 percent of the unstretched length) results in an expected fatigue life on the order of 10⁶ deformation cycles. As an example, a design utilizing resistance bands contains 1-foot-long resistance bands that are stretched 0.75 feet. The pulley system then requires a four to one distance traveled ratio to allow for 3 feet of user-end cable travel. While this design could prove to be useful, the added resistance requirement and increased forces acting on the frame are not ideal.

Instead of using resistance bands or coiled springs, a design utilizing constant force springs has increased height limiting potential. Throughout the extension of a constant force spring, the force output is constant. Consequently, there is no need to consider the unstretched length of the spring. This is a major advantage over the resistance band design because the interfacing device has more translational space afforded to it. As an example, a design utilizing 2-inch diameter constant force springs has an interfacing part positioned directly above the springs, approximately 2.5-inches from the base of the frame. The interfacing part is then able to translate approximately 1.5 feet within the resistance mechanism. The pulley system then requires a two to one distance traveled ratio to allow for 3 feet of user-end cable travel. The decreased distance traveled ratio therefore offers major weight and cost savings because less resistance output is required. Additionally, constant force output is more like gravitational resistance than the nonlinear force output of resistance bands, thereby creating a better lifting experience for the user. However, there are drawbacks to using constant force springs that must be considered. Mainly, the fatigue life of high resistance constant force springs is comparatively lower than resistance bands. Moreover, the design is more complex and requires a design that allows the user to easily replace fatigued parts. That said, the inventor considers the benefits of constant force spring to outweigh the drawbacks, and accordingly, the constant force spring design is recognized as the best mode.

In an exemplary approach to the design of the resistance mechanism, a structural metal frame contains multiple rails. A single transverse bar is slidably positioned along the rails and connected to multiple constant force springs. Each spring is connected by way of a rotatable shaft to an individual block that is slidably positioned on two rails, opposite the transverse bar. Rail sheaths are slidably positioned between the transverse bar and individual blocks to both maintain a base level distance and to stretch the springs a small amount, thereby creating a biasing force pulling the individual blocks towards the transverse bar. Individual blocks are shaped such that outer blocks slide freely along the rails if inner blocks are locked to the frame and inner blocks are locked to the frame if outer blocks are locked to the frame. To lock the individual blocks, two grooves are cut out of the faces of the individual blocks and slidable racks are inserted into the grooves. One groove is aligned for the rightmost individual blocks and is positioned above the other groove which is aligned for the leftmost individual blocks. The slidable racks are positioned at a distance from the individual blocks and specially shaped to prevent interference with adjacent individual blocks whilst still being able to lock a single individual block. Both racks are in mesh with a centrally located pinion that is fixed to a user interfacing dial. Turning the dial clockwise translates the racks towards the outermost blocks, thereby engaging more springs and increasing the resistance. An inelastic cable is fixed to the frame and routed through a pulley that is centrally located on the transverse bar, creating a 2 to 1 distance traveled ratio. The entire mechanism is contained within an encasing that can support the weight of the user.

In an exemplary approach to the resistance machine, two resistance mechanisms are connected to each outer using hinges. The hinges allow the resistance machine to be folded into a compact state for storage and unfolded for usage. Cable arms are slidably positioned along the side of the resistance mechanism encasing with an adjustable angle relative to the encasings. A 360-degree pulley is adjustably positioned at the end of each cable arm. Each cable arm has an inelastic cable attached to a carabiner clip on one end. The inelastic cable is routed through the cable arm and the encasing wherein it is attached to one of the resistance mechanisms. Selector dials protrude through both encasings and display the current selected resistance for each resistance mechanism. The user stands on the encasings in the unfolded position and pulls one or both inelastic cables via interfacing attachments, such as handles, to engage the resistance mechanisms that are connected to the specific inelastic cable. The carabiner clips allow for quick adjustments to user interfacing attachments. The user can fold the encasings and cable arms into a compact position for compact storage and portability. In total, one resistance machine weighs less than 40 lbs, outputs a maximum of 400 lbs in 20 lb increments, is contained within an 8-inch by 24-inch by 24-inch volume, and has maximum cable travel distances of 3 feet for each inelastic cable.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are incorporated in and constitute a part of the specification. The drawings, together with the general description given above and the detailed description of the exemplary embodiments and methods given below, serve to explain the principles of the invention. The objects and advantages of the invention will become apparent from a study of the following specification when viewed in light of the accompanying drawings, in which like elements are given the same or analogous reference numerals and wherein:

FIG. 1 is a perspective view of an embodiment of the resistance mechanism wherein resistance is provided by resistance bands;

FIG. 2 is a schematic showing the theoretical background of a pulley-based dependent motion system that has a distance of travel ratio of two to one;

FIG. 3 is a schematic showing the theoretical background of a pulley-based dependent motion system that has a distance of travel ratio of four to one;

FIG. 4 is a side view of an embodiment of the resistance mechanism demonstrating variable resistance by selectively locking one individual block;

FIG. 5 is a side view of an embodiment of the resistance mechanism demonstrating variable resistance by selectively locking three individual blocks;

FIG. 6 is a perspective view of an embodiment of the resistance mechanism wherein resistance is provided by constant force springs;

FIG. 7 is an exploded view of a constant force spring assembly that provides constant resistance force;

FIG. 8 is a perspective view of an embodiment of the resistance mechanism wherein resistance is provided by an electromagnet and the interfacing device contains pulleys;

FIG. 9 is perspective view of an embodiment of the resistance mechanism wherein resistance is provided by an electromagnet and the interfacing device contains spools;

FIG. 10 is a side view of an embodiment of the resistance mechanism wherein individual blocks are dependent on the translation of adjacent individual blocks;

FIG. 11 is a perspective view of an exemplary embodiment of the resistance mechanism with constant force springs, grooved dependent individual blocks, and a dial resistance selector;

FIG. 12 is a perspective view of an embodiment of the resistance mechanism with constant force springs and grooved dependent individual blocks;

FIG. 13 is a perspective view of a dial resistance selector assembly;

FIG. 14 is a perspective view of an exemplary embodiment of the resistance machine wherein resistance is selected with a dial;

FIG. 15 is a perspective view showing a user using the resistance machine for exercise;

FIG. 16 is a perspective view showing a user using two resistance machines with a platform accessory for exercise;

FIG. 17 is a perspective view showing the bottom two resistance machines in use with a platform accessory;

FIG. 18 is a perspective view showing a user using two resistance machines with a platform and arm accessories for exercise;

FIG. 19 is a perspective view showing the bottom of two resistance machines in use with a platform and cable arm accessories;

FIG. 20 is a perspective view showing an embodiment of the resistance machine wherein two resistance mechanisms are encased, connected by hinges, and unfolded for usage; and

FIG. 21 is a perspective view showing an embodiment of the resistance machine wherein two resistance mechanisms are encased, connected by hinges, and folded for storage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is to be understood that the disclosed embodiments of the invention are not limited to the detailed arrangements shown. The invention is capable of achieving similar results in other arrangements not shown. Additionally, the terminology used to describe the arrangements is for description only. The following terms and their associated meanings are explicitly defined below for the reader.

-   -   Embodiment—Describes an arrangement of a system that could prove         to be useful but is not considered to be the best mode by the         inventor.     -   Exemplary Embodiment—Describes an arrangement of a system that         is considered to be the best mode by the inventor.     -   Resistance Device—Describes any resistance providing element.         This can include resistance bands, springs, electromagnets,         motors, weighted plates, and other elements that function to         provide resistance.     -   Non-Gravitational Resistance Device—Describes any resistance         providing element that does not rely on gravity as its source of         resistance. This can include resistance bands, springs,         flywheels, electromagnets, motors, and other elements that         function to provide resistance without the use of gravity.     -   Distance Traveled Ratio—Describes the ratio of the distance         traveled by the user-interfacing inelastic cable to the         resistance device.     -   Interfacing Device—Describes any part or assembly of parts that         combine to alter the distance traveled ratio. An embodiment         without an interfacing device has a distance traveled ratio of         one to one.     -   Individual Block—Describes any object that is connected to one         end of a resistance device, can translate along rails, and can         be locked to another component of the system.     -   Fixed Individual Block—Describes any object that is connected to         one end of a resistance device and is permanently locked to         another component of the system.

The following list of components are referenced in the figures:

-   -   31. Frame     -   32. Transverse Bar     -   33. Individual Block     -   34. Resistance Band     -   35. Eye Hook     -   36. Inelastic Cable     -   37. Pulley     -   38. Rail     -   39. Rail Sheath     -   40. Pin Fixture     -   41. Locking Pin     -   42. Handle     -   43. Constant force Spring     -   44. Ball Bearing     -   45. Fixed Shaft     -   46. Electromagnet     -   47. Ferromagnetic Material     -   48. Connecting Cable     -   49. Computer     -   50. USB Cable     -   51. Dependent Individual Block     -   52. Grooved-Dependent Ind. Block     -   53. Grooved-Fixed Individual Block     -   54. Top Locking Rack     -   55. Bottom Locking Rack     -   56. Locking Pinion     -   57. Resistance Selecting Dial     -   58. Rubber Mat     -   59. Rubber Stopper     -   60. Carabiner Clip     -   61. Resistance Display     -   62. Inelastic Extension Cable     -   63. Resistance Machine Encasing     -   64. 360 Degree Pulley     -   65. Curl Bar     -   66. Platform     -   67. Olympic Bar     -   68. Cable Arms     -   69. Constant force Spring Assembly     -   70. Resistance Mechanism Assembly     -   71. Dial Selector Assembly     -   72. Resistance Machine Assembly     -   73. Rack and Pinion Gear Assembly     -   74. Driven Spool     -   75. Driving Spool     -   76. Rightmost Groove     -   77. Leftmost Groove     -   78. Adjustable Angled Pulley     -   79. Slidable Block     -   80. Hinges

FIG. 1 shows an embodiment for the resistance mechanism [70] which utilizes resistance devices [34]. The resistance devices may be extension springs, elastic bands, constant force springs, electromagnet-magnet pairings, or other lightweight resistance devices. The frame [31] has first [31 a] and second [31 b] ends, contains multiple parallel rails [38], and provides structural stability for the system. A transverse bar [32] and multiple individual blocks [33] are slidably positioned along the rails [38]. The transverse bar [32] contains a plurality of holes to allow the parallel rails [38] to pass therethrough to allow the transverse bar to slide along the parallel rails [38]. The individual blocks [33] are positioned proximate to the second end of the frame [31 b] and the transverse bar [32] is positioned opposite to the individual blocks [33] at approximately the middle of the parallel rails [38]. The resistance devices [34] are preferably pre-stretched and attached to both the transverse bar [32] and individual blocks [33] by means of fasteners [35], biasing the transverse bar [32] towards the individual blocks [33]. Each resistance device [34] includes a first end [34 a] attached to the transverse bar [32] and a second end [34 b] attached to one of the individual blocks [33]. Distance maintaining devices [39] are slidably positioned on the rails [38] between the transverse bar [32] and individual blocks [33] to separate the transverse bar [32] and the blacks [33] by a predetermined distance. Locking fixtures [40] are secured to the frame [31] and contain slots for locking pins [41]. Locking pins [41] are selectively inserted into the aligned slots of locking fixtures [40] and individual blocks [33], thereby mechanically locking the selected block [33] to the second end of the frame [31]. An inelastic cable [36] is fastened to the transverse bar [32], preferably to the middle of the transverse bar [32], to pull the transverse bar [32] away from the individual blocks [33], creating a biasing force only from the resistance devices [34] that are attached to locked individual blocks [33]. The combination of the distance maintaining devices [39] and stretched resistance devices [34] hold all unlocked individual blocks [33] at a constant position relative to the transverse bar [32]. A pulley [37] may be used to change the biasing direction of the inelastic cable [36]. The user interfaces with the inelastic cable [36] by pulling on a cable attachment [42] located at one end of the cable [36]. In FIG. 1 , there is no part or assembly of parts to refer to as the interfacing device. The distance traveled ratio is 1 to 1.

FIG. 2 and FIG. 3 are side views of an embodiment for the resistance mechanism [70] which utilizes resistance devices [34] with two different dependent motion systems. FIG. 2 and FIG. 3 are provided to illustrate the theoretical background for dependent motion systems. For both systems, the datum is chosen to be the first end of the frame [31 a]. The distances from the datum to the cable attachment [42] and the datum to the transverse bar [32] are defined as s_(e) and s_(a), respectively. Distances from the datum towards the second end of the frame [31 b] are defined as positive. In FIG. 2 , the inelastic cable [36] is fixed to the first end of the frame [31 a] and routed through a pulley [37]. The pulley [37] is fixed to the transverse bar [32], preferably the center of the transverse bar [32]. The interfacing device in this embodiment includes the transverse bar [32] and pulley [37] assembly. In FIG. 3 , the inelastic cable [36] is fixed to the first end of the frame [31 a] and routed through four pulleys [37]. Two pulleys [37] are fixed to the transverse bar [32] and the other two pulleys [37] are fixed to the first end of the frame [31 a]. The interfacing device in this embodiment includes the transverse bar [32] and four-pulley [37] assembly. The equations for the total length of the inelastic rope in FIG. 2 is

l ₁=2s _(a) −s _(e)  (1)

and

l ₂=4s _(a) −s _(e)  (2)

in FIG. 3 . Deriving these equations results in the second set of equations that describe the relative changes in distance traveled for the cable attachment [42] and transverse bar [32]. The relative change in distance for FIG. 2 is

Δs _(e)=2Δs _(a)  (3)

and

Δs _(e)=4Δs _(a)  (4)

for FIG. 3 . With these equations, the distance travel ratio is two to one in FIG. 2 and four to one in FIG. 3 .

FIG. 4 and FIG. 5 illustrate the variable resistance provided by successively locked resistance devices [34] in the resistance mechanism [70]. The inelastic cable [36] is routed through the pulleys [37] to control the translation of the transverse bar [32]. The resistance devices [34] are connected to the transverse bar [32] on one end and individual blocks [33] on the other. A locking mechanism (not shown) fixes a select number of individual blocks [33] to the frame [31]. In FIG. 4 , only the central individual block [33] is fixed to the frame [31]. In FIG. 5 , all individual blocks [33] are fixed to the frame [31]. When the user pulls the inelastic cable [36] (by way of the cable attachment [42]), tension in the inelastic cable [36] is generated by the resistance devices [34] attached to the fixed individual blocks [33]. Individual blocks [33] that are not fixed to the frame [31] move freely with the transverse bar [32]. With this system, the user can set a desired resistance depending on the number of engaged resistance devices [34]. The pulleys [37] are aligned such that a dependent motion system is created wherein the distance traveled ratio is four to one (see Eqn. 4). With this distance traveled ratio, the tension in the inelastic cable [36] is one-fourth that of the total resistance provided by the resistance devices [34].

FIG. 6 shows an embodiment for the resistance mechanism [70] which utilizes a resistance assembly [69], referred to herein as a constant force spring assembly. In this embodiment, the constant force spring assembly [69] replaces the resistance devices [34] shown in the embodiment of FIGS. 1-5 . As shown in FIG. 6 , there are only two resistance options available to the user; no resistance or full resistance. A skilled person in the art, however, would recognize that multiple constant force spring assemblies [69] may be used as illustrated in FIG. 1 , to provide different resistance options. The resistance assembly [69] is connected to the transverse bar [32] by the fastener [35]. The transverse bar [32] is then connected to the inelastic cable [36] by another fastener [35]. The constant force spring assembly [69] is attached to the individual block [33] and allows the constant force spring to rotate freely about its pinned axis via ball bearings (not shown). The individual block [33] is locked in place when the locking pin [41] is inserted through the pin fixture [40], and subsequently through the individual block [33]. When the individual block [33] is locked in place, the constant force spring [43] uncoils and exerts a biasing force on the transverse bar [32] toward the second end of the frame [31 b]. By pulling on the cable attachment [42], the user can create tension in the inelastic cable [36] if the individual block [33] is locked to the frame [31]. If the individual block [33] is not locked to the frame [31], no tension is generated in the inelastic cable [36] because the resistance assembly [69] is not engaged. The pulley [37] allows the user to pull and create tension in the inelastic cable [36] from various positions relative to the resistance mechanism assembly [70].

FIG. 7 illustrates the details of the constant force spring assembly [69] which includes an individual block [33] that provides resistance through a constant force spring [43], ball bearing [44], and fixed shaft [45]. The ball bearing [44] provides free rotation of the constant force spring [43] about the axis of the fixed shaft [45]. This fixed shaft [45] is fastened to the individual block [33] through a press-fit mechanism. The constant force spring [43] is attached to the transverse bar [32] to provide resistance when the individual block is engaged.

FIG. 8 and FIG. 9 show an embodiment of the resistance mechanism [70] utilizing an electromagnet [46]. The electromagnet [46] is fixed to the second end of the frame [31 b] and is controlled by a logic controller, such as a computer [49], via the USB cable [50]. When the electromagnet [46] is turned on by the computer [49], it generates a magnetic field that exerts a pulling force on the ferromagnetic material [47], biasing the ferromagnetic material [47] towards the electromagnet [46]. The strength of the magnetic field is proportional to the voltage supplied to the electromagnet [46]. This embodiment effectively replaces the resistance devices [34] in the embodiment of FIGS. 1-5 with the ferromagnet material [47] and the electromagnet [46]. By pulling on the cable attachment [42], the user generates tension in the inelastic cable [36] and forces the transverse bar [32] to move along the rails [38] towards the first end of the frame [31]. In FIG. 8 , the ferromagnetic material [47] is attached to the transverse bar [32] by a pair of fasteners [35] and a connecting cable [48]. The interfacing device in this embodiment includes the transverse bar [32] and a four-pulley [37] assembly. The pulleys [37] are aligned such that a dependent motion system is created wherein the distance traveled ratio is four to one (see Eqn. 4). In FIG. 9 , the ferromagnetic material [47] is attached to the transverse bar [32] through a press fit. The transverse bar [32] only functions to stabilize the system. The interfacing device in this embodiment consists of the spools [74, 75] wherein the driven spool [74] has a smaller radius than the driving spool [75]. The distance traveled ratio is equal to the ratio of the driving spool [75] radius to the driven spool [74] radius. FIG. 8 and FIG. 9 specifically show the differences between two dependent motion system arrangements that can provide the same function.

FIG. 10 illustrates another embodiment of resistance mechanism [70] wherein the motion of the individual blocks [51] are dependent on adjacent individual blocks [51]. Individual blocks [51] are slidably positioned along the rails [38], proximate to the second end of the frame [31]. A transverse bar [32] is placed opposite the individual blocks [33]. Resistance devices [34] are connected to the individual blocks [51] on one end and the transverse bar [32] on the other. When outer individual blocks [51] are locked to the second end of the frame [31], all inner individual blocks [51] leading up to the central “T-shaped” individual block [51] are also locked because of the geometric dependence on adjacent individual blocks [51]. The resistance devices [34] connected to the locked individual blocks [51] are engaged when the user pulls the cable attachment [42]. Locking only the center individual block [51] allows all other individual blocks [51] to freely move with the transverse bar [32]. The purpose of this design is two-fold: it decreases the space requirements of the resistance mechanism [70] and it allows multiple resistance devices [34] to be engaged from one locking point.

FIG. 11 shows an embodiment for the resistance mechanism [70] which utilizes constant force springs [43]. The frame [31] has first [31 a] and second [31 b] ends, contains multiple parallel rails [38], and provides structural stability for the system. A transverse bar [32] and multiple individual blocks [52] are slidably positioned along the rails [38]. The central individual block [53] is fixed to the second end of the frame [31 b]. The individual blocks [52] are also placed proximate to the second end of the frame [31 b] and the transverse bar [32] is placed proximate to the middle of the frame [31], between the first [31 a] and second [31 b] ends. The constant force springs [43] are pre-stretched and attached to the transverse bar [32] using fasteners [35]. The constant force springs [43] are attached to the individual blocks [52, 53] by means of constant force spring assemblies [69]. These connections bias the transverse bar [32] towards the individual blocks [52, 53]. Distance maintaining devices [39] are slidably positioned on the rails [38] between the transverse bar [32] and individual blocks [52, 53]. The individual blocks [52] are shaped such that the translation of adjacent individual blocks [52] are dependent on one another. The fixed individual block [53] is centered and fixed to the frame [31] to maintain a constant biasing force towards the second end of the frame [31 b]. Front-facing grooves [76, 77] are milled out of individual blocks [52, 53]. The rightmost groove [76] is aligned such that it is positioned above the leftmost groove [77]. The groove for the central individual block [53] is comprised of both rightmost [76] and leftmost [77] grooves. A rack and pinion assembly [73] is used to selectively lock individual blocks [52] to the frame [31]. The top rack [54] is inserted into the rightmost groove [76] and is in mesh with the top of the pinion [56]. Another bottom rack [55] is inserted into the leftmost groove [77] and is in mesh with the bottom of the pinion [56]. A user interfacing dial [57] is fixed to the pinion [56] to control the rotation of the pinion [56] and therefore the position of the racks [54, 55]. Aligning the racks [54, 55] with a specific individual block [52] locks the specific individual block [52] along with all individual blocks [52] adjacently located towards the central fixed individual block [53] because of the individual blocks [52] translational dependence. In the depicted locking position, outermost individual blocks [52] are disengaged and free to translate with the transverse bar [32] whilst the two innermost individual blocks [52] are locked to the frame. At the fully unlocked position, both racks [54, 55] are aligned with the groove on the fixed individual block [53]. In this position, only the fixed individual block [53] is engaged and individual blocks [52] translate with the transverse bar [32]. An inelastic cable [36] is fastened to the first end of the frame [31] and routed through a pulley [37] that is fixed to the transverse bar [32]. The inelastic cable is pulled by the user and creates a biasing force only from the constant force springs [43] that are attached to locked individual blocks [52, 53]. The combined forces of the distance maintaining devices [39] and stretched constant force springs [43] hold all unlocked individual blocks [52] at a constant position relative to the transverse bar [32]. The interfacing device in this embodiment consists of the transverse bar [32] and pulley [37] assembly and yields a two to one distance traveled ratio.

FIG. 12 shows an embodiment for the resistance mechanism [70] which utilizes resistance devices [43]. FIG. 12 contains the same parts as in FIG. 11 , however, the locking assembly [73] is removed for illustrative clarity. In particular, the grooves on the individual blocks [52, 53] are shown to complete the view of the entire mechanism.

FIG. 13 shows the details of the rack and pinion gear assembly [73] used for adjusting the resistance of the resistance mechanism [70]. The pinion [56] is fixed to the dial [57]. The gear teeth of the pinion [56] mesh with the gear teeth of both the top rack [54] and the bottom rack [55]. When the user turns the dial [57], the locking pinion [56] rotates, causing the top rack [54] and bottom rack [55] to move laterally in opposite directions relative to each other. When the edges of the racks [54 e, 55 e] are aligned with grooves for individual blocks [52] (as in FIG. 11 ), the individual blocks [52] are held in place by the racks [54, 55]. The alignment of the racks [54, 55] therefore effectively changes the resistance by engaging resistance devices [34] that are connected to the locked individual blocks [52].

FIG. 14 shows an embodiment for a resistance machine [72] having a resistance mechanism [70] enclosed inside an encasing [63]. The encasing [63] may contain any embodiment of the resistance mechanism [70]. The encasing [63] is also preferably structurally able to support the weight of the user. A mat [58] is fixed to the encasing [63] for the user to stand upon. The dial [57] may be turned by the user to select different levels of resistance. The dial [57] is rotatably fixed to a rack and pinion assembly [73] that successively locks in individual blocks [51], as depicted in FIG. 11 . The selected resistance level is shown on the display [61]. The inelastic cable [36] is routed through the pulley [64]. The stopper [59] and carabiner clip [60] are fixed to the end of the inelastic cable [36] wherein the stopper [59] rests on the pulley [64] in the disengaged state. The stopper [59] prevents the inelastic cable [36] from falling into the encasing [63]. To engage resistance, the user stands upon the encasing [63] and pulls the end of the carabiner clip [60].

FIG. 15 shows the user exercising with the resistance machine [72]. To use the resistance machine [72], the user stands on the resistance machine encasing [63], preferably on the mat [58], to keep the resistance machine [72] stationary. By pulling on the cable attachment [65], the user creates tension in the inelastic cable [36] that engages the resistive forces of the resistance mechanism [70] within the resistance machine [72]. The pulley [64] allows the user to create tension in the inelastic cable [36] with the cable attachment [65] at various positions relative to the pulley [64].

FIG. 16 demonstrates the modular ability to use multiple resistance machines [72] simultaneously to add more resistance. The use of a platform [66] combines the resistance machines [72] into one system and allows the user to perform more exercises. The platform accessory [66] has first and second ends with a mat [58] for the user to stand upon. Two resistance machines [72] are fixed to the base of the platform accessory [66] and therefore are not shown in FIG. 16 . Multiple cable attachments [62, 67] are shown in this depiction. The inelastic extension cables [62] are connected on one end to the inelastic cable [36] using carabiner clips [60]. An Olympic bar [67] is connected to both inelastic extension cables [62] on the other end to simultaneously engage both resistance machines [72]. The inelastic cable extensions [62] function to give the user a different starting point for a specific exercise. In this example, the user is performing an overhead press. It is therefore useful for the user to start the exercise with the Olympic bar [67] at shoulder height. The inelastic cable extensions [62] prevent the resistance machines [72] from engaging resistance at undesirable positions, such as at the platform [66] base.

FIG. 17 shows the bottom of the platform [66] in FIG. 16 . The resistance machines [72] are fixed to the platform [66] to create a single resistance-providing system. The pulleys [64] protrude from the platform [66] to give the user access to the inelastic cables [36] (not shown).

FIG. 18 shows a user exercising with combined accessories [66, 68] to perform different exercises. The platform accessory [66] has first and second ends with a mat [58] for the user to stand upon. Two resistance machines [72] are fixed to the base of the platform accessory [66] and therefore are not pictured. The pulleys [64] are attached to resistance machines [72] and protrude from both ends of the platform accessory [66]. Additional arm accessories [68] are fixed to the first end of the platform accessory [66]. Pulleys [64] are mounted to the ends of the arm accessories [68]. Inelastic cable extensions [62] are attached to carabiner clips [60] and routed through the pulleys [64] that are fixed to the arm accessories [68]. The user interfaces with cable attachments [42] to perform a desired exercise. Utilizing this system allows the user to leverage a variety of angles for different exercises while maintaining high resistance levels.

FIG. 19 shows the bottom view of the system depicted in FIG. 18 . The resistance machines [72] are fixed to the platform [66] and the arm accessories [68] are pinned to the first end of the platform [66]. Inelastic cable extensions [62] are attached to carabiner clips [60] and routed through the pulleys [64] that are fixed to the arm accessories [68].

FIG. 20 and FIG. 21 show another embodiment for a resistance machine [72] having two resistance mechanisms [70] enclosed inside an encasing [63]. The encasing [63] may contain any embodiment of the resistance mechanism [70]. The encasing [63] has first [63 a] and second [63 b] ends that are connected by hinges [80] so that the resistance machine [72] can be folded, as in FIG. 21 . Both the first [63 a] and second [63 b] ends of the encasing contain resistance mechanisms [70] that operate independently of one another. The encasing [63] is also preferably structurally able to support the weight of the user. Cable arms [68] are attached to the encasing [63] via an adjustable pulley [78] and a slidable block [79]. The adjustable pulley [78] and the slidable block [79] allows the position of the cable arms [68] to be changed for different exercises. Two inelastic cables [36] are routed through the cable arms [68] and connected to cable attachments [42] on a first end and resistance mechanisms [70] on a second end. The user stands on the resistance machine [72] and pulls on either one or both cable attachments [42] to engage either one or both of the resistance mechanism [70].

Although certain presently preferred embodiments of the invention have been specifically described herein, it will be apparent to those skilled in the art to which the invention pertains that variations and modifications of the various embodiments shown and described herein may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the invention be limited only to the extent required by the appended claims and the applicable rules of law. 

What is claimed is:
 1. A resistance mechanism comprising a. a frame having a plurality of parallel rails within the frame; b. a transverse bar having at least one opening through which the plurality of parallel rails passes; c. at least one block having holes through which one or more of the parallel rails passes; d. at least one locking fixture fixed to the frame and configured to removably secure at least one block to the frame; and e. at least one resistance device connecting each block to the transverse bar in a manner which biases the transverse bar towards the connected block when the connected block is secured to the frame.
 2. The resistance mechanism of claim 1, wherein there are a plurality of blocks.
 3. The resistance mechanism of claim 1, wherein the locking fixture comprises a rack and pinion gear assembly.
 4. The resistance mechanism of claim 1, wherein the resistance devices are comprised of elastic bands, springs, flywheels, electromagnets, motors, or combinations thereof.
 5. The resistance mechanism of claim 1, wherein the resistance devices are constant force springs.
 6. The resistance mechanism of claim 1, further comprising a plurality of rail sheaths slidably positioned on the parallel rails between the transverse bar and each block.
 7. The resistance mechanism of claim 1, further comprising an inelastic cable with first and second ends, the first end is connected to the transverse bar, the second end is positioned through the frame.
 8. The resistance mechanism of claim 7, further comprising inelastic cable extensions attached to the inelastic cables.
 9. The resistance mechanism of claim 7, wherein the inelastic cable is lead through one or more pulleys, spools, gears, belts, or combinations thereof in a manner which decreases the distance of travel of the transverse bar as compared to the distance of travel of the second end of the inelastic cable.
 10. The resistance mechanism of claim 7, further comprising at least one cable arm through which an inelastic cable is led, each cable arm comprises a. a first end that is adjustably attached to the frame and adjustably positioned to extend away from the frame; and b. a second end wherein the second end of the inelastic cable is positioned through the second end of the cable arm.
 11. A resistance machine comprising at least one encasing, each encasing enclosing at least one resistance mechanism, wherein each resistance mechanism is comprised of a. a frame having a plurality of parallel rails within the frame; b. a transverse bar having at least one opening through which the plurality of parallel rails passes; c. at least one block having holes through which one or more of the parallel rails passes; d. at least one locking fixture fixed to the frame and configured to removably secure at least one block to the frame; e. at least one resistance device connecting each block to the transverse bar in a manner which biases the transverse bar towards the connected block when the connected block is secured to the frame; and f. an inelastic cable with first and second ends, the first end is connected to the transverse bar, the second end is positioned to through the frame.
 12. The resistance machine of claim 11, wherein each encasing is connected to a structural element that provides a means of supporting a user's weight.
 13. The resistance machine of claim 12, wherein the structural element is a platform, seat, bench, or combination thereof.
 14. The resistance machine of claim 10, further comprising at least one cable arm through which an inelastic cable is led, each cable arm comprises a. a first end that is adjustably attached to an encasing and adjustably positioned to extend away from the encasing; and b. a second end wherein the second end of the inelastic cable is positioned through the second end of the cable arm.
 15. The resistance machine of claim 10, wherein there are a plurality of blocks in each frame.
 16. The resistance machine of claim 10, wherein the locking fixtures comprise a rack and pinion gear assembly.
 17. The resistance machine of claim 10, wherein the resistance devices are comprised of constant force springs.
 18. The resistance machine of claim 10, wherein the inelastic cable is lead through one or more pulleys, spools, gears, belts, or combinations thereof in a manner which decreases the distance of travel of the transverse bar to the distance of travel of the second end of the inelastic cable.
 19. The resistance machine of claim 10, further comprising inelastic cable extensions attached to the inelastic cables.
 20. A method for making a resistance machine, the method comprising the steps of a. providing a frame having a plurality of parallel rails within the frame; b. providing a transverse bar having a plurality of holes through which the plurality of parallel rails passes; c. providing at least one block having holes through which one or more of the parallel rails passes; d. connecting at least one resistance device with first and second ends to a block on the first end and the transverse bar on the second end; e. fixing a locking fixture to the frame, the locking fixture is configured to removably secure each block to the frame; and f. connecting an inelastic cable to the transverse bar and positioned through the frame such that the inelastic cable is configured to pull the transverse bar away from each block. 